Early procurement of scarlet macaws and the emergence of social complexity in Chaco Canyon, NM

Abstract

High-precision accelerator mass spectrometer (AMS) (14)C dates of scarlet macaw (Ara macao) skeletal remains provide the first direct evidence from Chaco Canyon in northwestern New Mexico that these Neotropical birds were procured from Mesoamerica by Pueblo people as early as ∼ A.D. 900-975. Chaco was a prominent prehistoric Pueblo center with a dense concentration of multistoried great houses constructed from the 9th through early 12th centuries. At the best known great house of Pueblo Bonito, unusual burial crypts and significant quantities of exotic and symbolically important materials, including scarlet macaws, turquoise, marine shell, and cacao, suggest societal complexity unprecedented elsewhere in the Puebloan world. Scarlet macaws are known markers of social and political status among the Pueblos. New AMS (14)C-dated scarlet macaw remains from Pueblo Bonito demonstrate that these birds were acquired persistently from Mesoamerica between A.D. 900 and 1150. Most of the macaws date before the hypothesized apogeal Chacoan period (A.D. 1040-1110) to which they are commonly attributed. The 10th century acquisition of these birds is consistent with the hypothesis that more formalized status hierarchies developed with significant connections to Mesoamerica before the post-A.D. 1040 architectural florescence in Chaco Canyon.

Keywords: Chaco Canyon; archaeology; scarlet macaws; sociopolitical complexity.

Fig. 1.

(A) Scarlet macaws, (B) the historic range of scarlet macaws, (C) locations of sites cited in text or with larger concentrations of macaws in the SW, and (D) a prehistoric feather bundle (H/13338) from Allen Canyon in Grand Gulch.

Fig. 2.

Plan view of Pueblo Bonito with the earliest construction highlighted in red. The locations of the elite burial crypt, room 33, and the three rooms with dated macaw samples are highlighted.

Fig. 3.

Calibrated posterior probability distributions for directly AMS ¹⁴C-dated macaw bones from Chaco Canyon [Pueblo Bonito rooms 38 (red), 71 (yellow), and 78 (green); Mimbres region Old Town (blue) and Mitchell (brown); and Allen Canyon in Grand Gulch (black)]. Brackets below distributions indicate 1σ and 2σ calibrated ranges.

Fig. 4.

Modeled distributions of AMS ¹⁴C dates on Pueblo Bonito macaws as well as human burial dates and stratigraphic data (16) from room 33 relative to total construction effort (17) in Chaco Canyon. Macaws and burials were grouped and combined in OxCal based on ¹⁴C ages, and stratigraphic data from room 33 was incorporated in a sequence model.

Fig. S1.

Calibrated AMS ¹⁴C dates on 14 macaws from Pueblo Bonito plotted on the IntCal13 curve show the effects of plateaus and reversals on the resulting distributions and overall temporal patterning of the calibrated data.

Fig. S2.

Frequency of 210 simulated conventional ¹⁴C ages (gray) from calibrated A.D. 750–1250 shows periods likely to be over- and underrepresented in a random dating sample vs. the observed ¹⁴C ages of 14 Pueblo Bonito macaws (red). Although the overall structure of the macaw data is partly driven by the shape of the calibration curve, frequencies with each group are not completely explained as an artifact of the curve.